I've done a dozen of these now. And my txt file looks good. I don't get an error either. But the jsx simply does nothing. No error, nothing.
I even ran an older jsx file that works against the new txt file with all the array of text and grep changes. Nothing again.
I compared the text and grep preferences to what I was asking it to do to the old one that works. I didn't spot anything.
So my question is what?!?!!?!?!!?!? @!*(#&*(#&* 
I am assuming that without an error that the script runs fine, that the actual language of the text and grep prefs are what CS3 does not like because it doesnt execute it.
This is very very basic. It looks for a string of any of these bylines in a "Body" style and changes it to "Byline" style. Works perfect in CS5, so I'm flabbergasted.
//Find this string of news agencies in body and change to byline
grep {findWhat:"^The New York Times News Service\\r|^The Washington Post Writers Group\\r|^Associated Press\\r|^Bloomberg News\\r|^Canadian Press\\r|^Daily Telegraph\\r|^Financial Post\\r|^National Post\\r|^National Post wire services\\r|^New York Times\\r|^Postmedia News\\r|^Reuters\\r|^Slate.com\\r|^The Associated Press\\r|^The Canadian Press\\r|^The Daily Telegraph\\r|^The Media Line\\r|^The New York Times\\r|^Weekend Post\\r|^The New York Times News Service,\\r|^The Washington Post Writers Group,\\r|^Associated Press,\\r|^Bloomberg News,\\r|^Canadian Press,\\r|^Daily Telegraph,\\r|^Financial Post,\\r|^National Post,\\r|^National Post wire services,\\r|^New York Times,\\r|^Postmedia News,\\r|^Reuters,\\r|^Slate.com,\\r|^The Associated Press,\\r|^The Canadian Press,\\r|^The Daily Telegraph,\\r|^The Media Line,\\r|^The New York Times,\\r|^Weekend Post,", appliedParagraphStyle:"Body"} {appliedParagraphStyle:"Byline"} {includeLockedStoriesForFind:false, includeLockedLayersForFind:false, includeHiddenLayers:false, includeMasterPages:false, includeFootnotes:true, kanaSensitive:true, widthSensitive:true}